Originally Posted by
oddjob2
You probably already have a long cage RD, as it is a mtb, so no need to change. However, you will likely need a longer chain.
+1 Depending on how well used the bike is, you will likely want a new chain for sure to go with the new cassette. Search Amazon or eBay, both can likely be had for under $30 total. SRAM 830 chain with their quick link is cheap, so is a Sunrace cassette.